PROJECT SUMMARY During young adulthood, drinking dramatically increases, with binge-level drinking peaking at age 22 and nearly half of individuals reporting binge-level alcohol use. Frequent binge alcohol use during the protracted neuromaturation spanning into the mid-20s may result in greater brain and cognitive effects than similar alcohol use in later adulthood. In response to RFA-AA-17-003, this application proposes a Research Project Site of the National Consortium on Alcohol and Neurodevelopment in Adolescence second phase (NCANDA-2) to determine the predictors and effects of heavy alcohol use in adolescence and young adulthood. To achieve this, the Pittsburgh site of NCANDA-2 will continue to follow a cohort of 125 Pittsburgh-area (n=831 across all 5 sites) participants (ages 12-21 at baseline first visit) to acquire the necessary data to advance our understanding of adolescent development and the effects of alcohol use during adolescence on the adult brain. NCANDA-2 will use multimodal neuroimaging, cognitive testing, behavioral assessment, biospecimen collection, and ecological momentary assessment. The examination of alcohol consequences will focus on structural and functional maturation of brain areas that actively develop during adolescence, are involved in psychological regulation, respond to rewards, and appear vulnerable to neurotoxic effects of alcohol. In addition, the Pittsburgh site will collaborate with the SRI sites to study sleep-related predictors and effects of alcohol use in a subgroup of adolescents. Pittsburgh will also collaborate with the Duke site to collect the Rewarded Antisaccade fMRI task to evaluate changes in the reward and cognitive control systems in relationship to alcohol use. Sex differences in development, alcohol use patterns, impact of alcohol use on the brain, and sex-differentiating psychosocial factors (e.g., depression symptoms) will be considered in analyses. With the additional longitudinal data provided by this renewal, we will determine the effects of alcohol exposure on the developmental trajectory of the adolescent human brain, and identify preexisting psychobiological vulnerabilities that may put an adolescent or young adult at elevated risk for an alcohol use disorder.